Active RFID Tag Arrangements for Actuation of Downhole Equipment in Well Fluids

ABSTRACT

A first RFID tag arrangement for actuating a downhole tool includes a non-metallic housing enclosing a passive RFID tag, power source, pulsed oscillator circuit, and energizer coil. The pulsed oscillator circuit drives the energizer coil to stimulate and activate the tag such that it can be read by an external reader. A second RFID tag arrangement includes a non-metallic housing enclosing a power source, a transmission circuit, and a transmitter coil. The transmission circuit can drive the transmitter coil to transmit a payload stored in the transmission circuit such that the payload is delivered to an external reader. A method of actuating a downhole tool includes placing the tool&#39;s RFID tag reader in listen only mode, introducing into the wellbore an active RFID tag that transmits its payload to the reader, and optionally configuring the reader to reprogram the tag when it receives the payload therefrom.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. application Ser. No. 15/747,421 filed 24Jan. 2018, which is a 371 application of International Appl.PCT/US2016/044235 filed 27 Jul. 2016, which claims the benefit of U.S.Prov. Appl. 62/202,267 filed 7 Aug. 2015, each of which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE

In various oil and gas operations, it is desirable or even necessary tooperate tools that are located in a wellbore drilled from the surfacethat penetrates a hydrocarbon bearing formation. Such operations caninclude opening or closing valves, activating or deactivating tools, andthe like. Historically, a variety of techniques have been developed toperform such operations. One example is pressure actuation, in which thepressure in the wellbore can be manipulated by pumps at the surface toinduce a desired action. In another variation, plugs, balls, darts, andthe like can be dropped into a wellbore or a tubular disposed therein,eventually seating on a mechanism that performs the desired operation.With the development of ever more sophisticated tools and wellboreenvironments, other actuation techniques have been developed, includingthe use of Radio Frequency Identification Transponders, also known asRFID tags.

One example of a downhole tool arrangement actuated by an RFID tag isdisclosed in applicant's co-pending published U.S. patent applicationbearing publication number 2014/0305662, which is hereby incorporated byreference in its entirety. In general, this and other RFID embodimentsoperate by designing a downhole RFID receiver into the tool. This RFIDreader will respond to an RFID tag encoded with the appropriate datapayload to actuate the tool. When it is desired to actuate the tool, oneor more RFID tags having the appropriate data payload can be introducedinto the wellbore and, upon arrival at the RFID reader of the tool, willcause actuation of the tool. In some embodiments, the RFID reader anddownhole tool can be configured for further actuation or reversal ofactuation when an RFID tag encoded with a different corresponding datapayload is detected. In such cases, when it is desired to furtheractuate or reverse the actuation of the tool, and RFID tag can beintroduced into the wellbore or a tubular thereof.

RFID tags come in two broad categories. Active RFID tags have their ownpower source, typically a battery, and are typically configured tocontinuously transmit their data payload. When they come within range ofan Active RFID detector, which can be configured as a “listen only”device, the Active RFID detector will detect the transmitted signal andrespond according to its program. Passive RFID tags do not have theirown power source, and are powered by a passive RFID tag reader.Generally, a passive RFID tag reader emits a relatively high frequencyelectromagnetic field (VHF band). This field stimulates a coil in thepassive RFID tag that then charges a capacitor within the passive tagthat serves as the passive tag's power source. Once the capacitor ischarged, the passive tag begins transmitting its payload (typically inthe LF band) until the charge in the capacitor is depleted. Thistransmitted signal is detected by the passive RFID tag reader.

In some embodiments it may be desirable to use an active tag versus apassive tag. The reasons for this can vary. One distinction betweencommercially available active and passive tags is operating frequency.Heretofore, passive tags used in downhole tool operation have typicallyoperated in the LF range, while most commercially available active tagsoperate in the UHF range. Also, many passive tags operate using FM(frequency modulated) or FSK (frequency shift keying) while manycommercially active tags operate using AM (amplitude modulated) or ASK(amplitude shift keying) for encoding data. Also, many active tagsand/or active tag readers are not designed to accommodate the highoperating temperatures, pressures, and vibration levels associated withdownhole operation. Finally, there is an existing base of downhole toolsthat are designed around various existing passive reader technologies,and adapting these to conventional active tags would require significantredesign of antennas, transceivers, and the like. Thus, what is neededis a mechanism to adapt preexisting passive RFID tags for active modeoperation or to otherwise simulate the operation of such preexistingRFID tags with an active RFID tag design.

SUMMARY OF THE DISCLOSURE

Disclosed herein is a first RFID tag arrangement for actuating adownhole tool located in a wellbore. The first RFID tag arrangement caninclude a non-metallic housing having disposed therein a passive RFIDtag, electrical power source, pulsed oscillator circuit and energizercoil. The electrical power source can power the pulsed oscillatorcircuit to drive the energizer coil to stimulate and thereby activatethe passive RFID tag such that the tag may be read by an RFID tag readerexternal to the RFID tag arrangement. The first RFID tag arrangement canbe adapted to include a passive RFID tag that is programmable, and/or sothat the electrical power source can be a battery, capacitor, or otherpower source.

Also disclosed herein is a second RFID tag arrangement for actuating adownhole tool located in a wellbore. The second RFID tag arrangement caninclude a non-metallic housing having disposed therein an electricalpower source, a transmission circuit, and a transmitter coil. Theelectrical power source can configure the transmission circuit to drivethe transmitter coil to transmit a payload stored in the transmissioncircuit via the coil such that the tag arrangement may be read by anRFID tag reader external to the RFID tag arrangement. The second RFIDtag arrangement can be adapted so that the transmission circuit isprogrammable, and/or so that the electrical power source can be abattery, capacitor, or other power source.

Also disclosed herein is a method of actuating a downhole tool designedto be used with a passive RFID tag using an active RFID tag instead. Themethod can include placing an RFID tag reader of the downhole tool in alisten only mode in which the RFID tag reader does not transmit astimulation signal to a tag. The method can further include introducinginto the wellbore an active RFID tag that transmits its payload to theRFID tag reader without stimulation by the RFID tag reader. The methodcan still further include configuring the RFID tag reader to transmit asignal to the active RFID tag reconfiguring the tag when it receives thepayload from the active RFID tag. The active RFID tag can be either thefirst or second RFID tag arrangements discussed above, or can be anotheractive RFID tag design.

The foregoing summary is not intended to summarize each potentialembodiment or every aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of an energizer RFID tag for use with apassive RFID tag reader.

FIG. 2 illustrates an alternative embodiment of an energizer RFID tagfor use with a passive RFID tag reader.

FIG. 3 illustrates an embodiment of a custom active RFID tag for usewith a passive RFID tag reader.

FIGS. 4A-4F illustrate embodiments of tag delivery systems for thedisclosed energizer RFID tag and custom active RFID tag of the presentdisclosure.

DETAILED DESCRIPTION

Illustrated in FIG. 1 is an Energizer RFID tag 100 created by adapting apassive RFID tag. The Energizer RFID tag 100 includes a non-metallichousing 102. For use in downhole operations, this non-metallic housing102 can be designed to accommodate the desired range of downholeoperating temperatures, pressures, and vibration levels, and can also bedesigned to be “intrinsically safe” for operation in explosive and/orcombustible environments. Other design considerations with respect tohousing 102 is that it be made of a material that is easily drillableand/or otherwise retrievable from the wellbore so that it does notinterfere with any subsequent operations required in the wellbore.

Disposed within housing 102 is a conventional passive RFID tag 104. Thiscan be any of a variety of commercially available tags, such as theTexas Instruments RI-TRP-WR3P, which is a read/write capability a/k/aprogrammable tag. Also disposed within housing 102 is a battery 106, aprinted circuit board 108 containing a pulsed oscillator circuit, and anenergizer coil 110. The pulsed oscillator circuit, powered by thebattery, sends a charge cycle via the energizer coil 110 to the passiveRFID tag. In one embodiment, the charge cycle can have a duration of16-ms. The RFID tag 104 charged by the energizer coil 110 can thenbroadcast its pre-programmed payload. In some embodiments, the payloadcan be 12 bytes programmed by the user. In some embodiments, thistransmit phase can have a duration of 14-ms. After the transmit phase,the circuit then returns to charge cycle and the pattern repeats.

If the passive RFID tag is located proximate an antenna, the transmittedpayload will be received by the tool and acted upon according to thetool's programming. In some embodiments, the reader's antenna isarranged such that it will surround the tag as it propagates downhole,and thus the tag will typically be read when the tag is located withinan external antenna surrounding the tag. Importantly in theseembodiments, the external antenna and RFID receiver can be operated in“listen mode.” In such a mode, the reader does not emit anelectromagnetic signal that influences the energizer tag or the passivetag within. This mode of operation can be advantageously employed toincrease the battery life of the tool, since the RFID reader needs tooperate only in a listen mode, thus it need not send the charging pulseto the tag. Additionally, the potential for interference with readingthe tag due to the charge pulse is reduced when operated in the listenonly mode. Alternatively, the antenna on the tool can be configured toeither transmit/receive for conventional passive tags. In either case, afurther advantage of the energizer tag arrangement described above isthe ability to adapt it to existing passive RFID tags.

An alternative embodiment of the energizer tag arrangement isillustrated in FIG. 2, in which like reference numerals to FIG. 1 havebeen used. In FIG. 2, the illustration of housing 102 has been omitted.Otherwise, it can be seen that Energizer RFID tag 100 includes a passiveRFID tag 104 as described above. Energizer tag also contains battery108, and energizer coil 110, and an ASIC 112 that includes the describedoscillator circuit. Each of these components is mounted on or within aprinted circuit board 108. The interconnection and operation of thesecomponents is as described above with respect to FIG. 1.

In some embodiments, it might be desirable to configure a downhole toolhaving a conventional passive RFID tag reader to operate in a “sleepmode” corresponding to the listen only mode described above. The toolcould be further configured to “wake up” in response to the detection ofan energizer tag as described above. In the awakened mode, the downholetool could operate as a conventional passive tag reader, such that itwould begin stimulating passive tags (if present) and would respond toarrival of such passive tags as programmed.

As an alternative to the energizer tag arrangement described above, itis also possible to create a custom active RFID tag by directly couplinga battery to an already existing passive RFID electrical circuit. Anelectrical circuit as described above with the energizer coilarrangements could also be installed to be used as a timing coil.

In still other embodiments, an exemplary custom active tag 200 isillustrated in FIG. 3. The custom active tag 200 can include a printedcircuit board 208, which can serve as a mounting point for the remainingcomponents. Custom active tag 200 can also include a battery 206, whichcan be, for example, a Lithium Thionyl Chloride Primary Cell. In someembodiments it might be desirable to make such a battery fromcommercially available AA or AAA cells. In some embodiments, a 3.6Vbattery may be desired, necessitating the use of three such AA or AAAcells. As in the embodiments discussed above, an ASIC 212 and a customwound coil 210 may also be provided. As in the energizer tagarrangement, such parts would be enclosed within a suitable non-metallichousing allowing for waterproofing, pressure, temperature, and vibrationresistance, etc. for components within. Additionally, as noted, it maybe desirable for the housing to be easily drillable and/or otherwiseremovable from the wellbore so as to reduce or eliminate interferencewith subsequent wellbore operations.

In a departure from the energizer tag arrangement described with respectto FIGS. 1 and 2, in the custom active tag arrangement of FIG. 3, theASIC 212 powered by the battery 206, sends a transmit cycle of a payloadheld on the ASIC 212 via the coil 210. It can then rest for some periodof time (to conserve battery), and re-start the transmit cycle and soon. In some embodiments, it might be desired to configure the payload,transmit, and rest cycles so that they correspond to those of apreexisting passive tag design. In one embodiment, the payload can be 12bytes and can optionally be hard coded onto the ASIC 212. Alternatively,the ASIC 212 can be programmable in much the same way as theprogrammable tags described above. Additionally, the transmit and restcycles can be configured to be 14-ms and 16-ms, respectively, tocorrespond to those used with a particular passive tag and the energizertag arrangement described above. It will be appreciated by those skilledin the art that any operational parameters desired may be employed andprogrammed on the ASIC 212 for operation with any of a variety ofexisting or custom designed tools.

There are a variety of advantages achievable as a result of the customactive tag arrangement described above with respect to FIG. 3. Forexample, the custom active tag 200 can have lower power requirements,extending the battery life of the tag 200 as compared to the energizertag arrangement. Additionally, such a custom active tag arrangementprovides the same benefit of extended battery life in the downhole toolbecause the downhole tool can be, but need not be, operated in a listenonly mode. Additionally, as with the energizer tag, there may be reducedinterference with reading of the tag 200 because of the absence of thecharge pulse in a conventional passive tag arrangement. Finally, becausethe custom active tag 200 described with respect to FIG. 3 is based onall custom componentry, it can be designed to have higher temperatureand other ratings than the passive tag it is designed to emulate. As anexample, battery 206 can be replaced with a capacitor for highertemperature operation, and the semiconductor components such as ASIC 212can be designed for high temperature operation using known semiconductortechnologies and design techniques.

With either of the foregoing tag designs, i.e., the energizer tagarrangement in FIGS. 1 and 2 or the custom active tag arrangement inFIG. 3, multiple transmission antennas could be installed within thehousing at multiple angles such that their effective transmission fieldcould be effectively increased to cover a higher allowable angle of thetag with respect to the reading antenna.

Also with either of the foregoing designs, a downhole tool for use withthe tags 100, 200 could be configured so that when the tool receives asignal from the tag 100, 200, the tool then transmits a signal to theRFID tag 100, 200 re-programming the payload of the tag 100, 200. TheRFID tag 100, 200 could then be displaced further into the well and thenew payload could be used to actuate a further tool located down thewell.

It will be appreciated by those skilled in the art that the tagarrangements described herein can be used with any of a variety ofdownhole RFID actuated tools and RFID tag delivery systems, including byway of example but not limitation, any of the operations described inapplicant's co-pending U.S. application Ser. No. 15/153,421, filed 12May 2016, and entitled “RFID Tag Delivery System,” which is herebyincorporated by reference in its entirety. In particular, FIGS. 4A-4Cillustrate a tag carrier 50 and an RFID tag 300 of a tag delivery systemaccording to the present disclosure. The RFID tag 300 can be anEnergizer RFID tag 100 according to the energizer tag arrangement inFIGS. 1 and 2 or can be a custom active RFID tag 200 according to thecustom active tag arrangement in FIG. 3.

Here, the tag carrier 50 can be a dart. As shown in FIGS. 4A-4C, thedart 50 includes a mandrel 52 (composed of a relatively stiff andnon-conductive material, such as an engineering polymer or fiberreinforced composite) and includes a finned seal 56 (composed of arelatively flexible material such as an elastomer or elastomericcopolymer). As shown in FIGS. 4A-4C, the dart 50 may have a catchelement 54, such as a ball stud or the like.

As shown in FIG. 4A, the mandrel 52 may have a nose formed at a leadingend thereof. A receptacle 58 formed in the nose can hold the RFID tag300, and a cap may retain the RFID tag 300 in the receptacle 58. TheRFID tag 300 would thereby be centralized in a bore of a surroundingtubular, allowing confidence in using only one RFID tag 300 tocommunicate with a control sub.

As shown in FIG. 4B, an RFID tag 300 may be located in or on a fin 56.The RFID tag 300 would thereby be located close to an inner surface of asurrounding tubular, potentially closer to an antenna (not shown) thanwhen centralized. Closer proximity of the RFID tag 300 to the antennamay provide better transmission of command signals. When located on afin 56, it may be desirable to affix the RFID tag 300 to the “back” ofthe fin 56—the surface nearest the mandrel 52—so that the fin 56shelters the RFID tag 300 during downhole travel.

Further, more than one RFID tag 300 can be used on a dart 50, such asshown in FIG. 4C. Here, the dart 50 includes an RFID tag 300 centrallylocated in the nose receptacle 58 and includes another RFID tag 300located in the finned seal 56. These and other variations can be used.

FIG. 4D illustrates another tag delivery system of the presentdisclosure. The system includes a tag carrier 50 and an RFID tag 300.The tag carrier 50 may be a pump down plug, such as a dart. Again, thedart 50 may include a finned portion 56, a mandrel portion 52, and acatch element, such as a tail portion 58. The finned portion 56 mayinclude one or more (three shown) fins extending outward from an outersurface of the mandrel portion 52. The dart 50 may include a materialhaving sufficient flexibility, such as a foamed polymer likepolyurethane. A receptacle may be formed in the tail portion 58 of thedart 50, and the RFID tag 300 may be disposed in the receptacle. Asshown, the receptacle for the RFID tag 300 may be centrally locatedwithin the dart 50. The RFID tag 300 may be retained in the receptacle,for example, by bonding or interference fit.

A tag launcher (not shown) at surface or elsewhere launches the dart 50,and the dart 50 can be propelled by pumped fluid. The dart 50 travelsinto a control sub 80 and passes an antenna 84. If desired, the dart 50can travel until engaging a seat 82, which may be composed of arelatively stiff and nonconductive material, such as an engineeringpolymer or fiber reinforced composite.

As the RFID tag 300 comes in proximity to the antenna 84 by eitherpassing through the control sub 80 or at least temporarily engaging theseat 82, the RFID tag 300 communicates signals with the antenna 84 ofthe control sub 80. At that point, some form of operation can beperformed. As one brief example, a control circuit 86 of the sub 80 mayoperate an actuator (not shown) to shift a valve sleeve (not shown) toan open or closed position. As will be appreciated, any suitable form ofoperation, actuation, and the like can be performed in response to thecontrol signals provided by the RFID tag 300. Eventually, increasepressure pumped against the dart 50 may pass the dart through the throatof the seat 82.

FIG. 4E illustrates an alternative tag carrier 60 for use with a tagdelivery system. Instead of the tag carrier 60 being a dart, the tagcarrier 60 is another type of pump down plug, such as a pig having abody with a shape that is elongated or ellipsoid (i.e., a prolate) orshaped like an egg, a capsule, or a bullet. The pig 60 may be composedof a material having sufficient flexibility, such as a foamed polymer ofpolyurethane or the like. A receptacle 64 may be formed in a tailportion 62 of the pig 60, and the RFID tag 300 may be disposed in thereceptacle 64. The receptacle 64 may be centrally located within the pig60, and the RFID tag 300 may be retained in the receptacle by bonding orinterference fit.

Given its shape, the pig 60 may or may not sealingly engage a bore of atubular string as the pig 60 is pumped therethrough. Due to the curvedouter surface of the pig 60, the pig 60 may not be completely stoppedupon engagement with a shoulder, stop, lip, or seat (e.g., 82) of acontrol sub; however, the pig 60 may be sufficiently slowed to ensurecommunication between the RFID tag 300 and an antenna (not shown).

As another example, FIG. 4F illustrates another tag delivery system ofthe present disclosure. The system includes a tag carrier 50 and an RFIDtag 300 (e.g., Energizer RFID tag 100 or custom active RFID tag 200).The tag carrier 50 may be a pump down plug, such as a dart. Again, thedart 50 may include a finned portion 56, a mandrel portion 52, and acatch element, such as a tail portion 58. A receptacle may be formed inthe nose of the dart 50, and the RFID tag 300 is disposed in thereceptacle.

A tag launcher (not shown) at surface or elsewhere launches the dart 50,and the dart 50 can be propelled by pumped fluid. The dart 50 travelsinto a control sub 80 and passes an antenna 84. If desired, the dart 50can travel until engaging a seat 82. As the RFID tag 300 comes inproximity to the antenna 84 by either passing through the control sub 80or at least temporarily engaging the seat 82, the RFID tag 300communicates signals with the antenna 84 of the control sub 80. At thatpoint, some form of operation can be performed.

As these details of tag delivery systems show, the RFID tags 100, 200,and 300 of the present disclosure can be incorporated into a number oftag carriers in different ways. Moreover, the tag carrier can belaunched with an appropriate launcher at surface or elsewhere and canengage various stops, seats, etc. and pass various forms of antennas insubs downhole to achieve some form of operation.

The foregoing description of preferred and other embodiments is notintended to limit or restrict the scope or applicability of theinventive concepts conceived of by the Applicants. It will beappreciated with the benefit of the present disclosure that featuresdescribed above in accordance with any embodiment or aspect of thedisclosed subject matter can be utilized, either alone or incombination, with any other described feature, in any other embodimentor aspect of the disclosed subject matter.

In exchange for disclosing the inventive concepts contained herein, theApplicants desire all patent rights afforded by the appended claims.Therefore, it is intended that the appended claims include allmodifications and alterations to the full extent that they come withinthe scope of the following claims or the equivalents thereof.

What is claimed is:
 1. A Radio Frequency Identification (RFID) tagarrangement readable by an RFID tag reader for actuating a downhole toollocated in a wellbore, the RFID tag arrangement comprising: a housingbeing non-metallic; a circuit board disposed in the housing; atransmission circuit mounted on the circuit board and storing a payload;a transmitter coil mounted on the circuit board and disposed inelectrical communication with the transmission circuit; and anelectrical power source mounted on the circuit board and disposed inelectrical communication with the transmission circuit, wherein theelectrical power source powers the transmission circuit to drive thetransmitter coil to transmit the payload stored in the transmissioncircuit via the transmitter coil such that the RFID tag arrangement isreadable by the RFID tag reader external to the RFID tag arrangement. 2.The arrangement of claim 1, wherein the transmission circuit isprogrammable.
 3. The arrangement of claim 1, wherein transmissioncircuit is configured to transmit for a duration of 14-ms intransmission cycles and is configured to rest for a period of 16-msbetween the transmission cycles.
 4. The arrangement of claim 1, whereinthe payload is 12 bytes.
 5. The arrangement of claim 1, wherein theelectrical power source is a battery.
 6. The arrangement of claim 5,wherein the battery is selected from the group consisting of a LithiumThionyl Chloride Primary Cell, a 3.6V battery, one or more AA cells, andone or more AAA cells.
 7. The arrangement of claim 1, wherein theelectrical power source is a capacitor.
 8. The arrangement of claim 1,wherein the circuit board defines a slot in which the electric powersource is mounted.
 9. The arrangement of claim 1, wherein transmittercoil is affixed to extend from an end of the circuit board.
 10. Thearrangement of claim 1, wherein the transmission coil comprises multipletransmission antennas installed within the housing at multiple angles.11. The arrangement of claim 1, further comprising a carrier deployabledownhole in the wellbore to the downhole tool and having the housingwith the circuit board, the transmission circuit, the transmitter coil,and the electrical power disposed therein.
 12. The arrangement of claim1, wherein the carrier is selected from the group consisting of a plug,a ball, a dart, a pump-down plug, and a pig.
 13. A system for use in awellbore, the system comprising; a downhole tool for use in thewellbore, the downhole tool having a Radio Frequency Identification(RFID) tag reader placed in a listen only mode and configured to actuatethe downhole tool; and an RFID tag arrangement according to claim 1deployable downhole in the wellbore to the downhole tool.
 14. A methodof actuating a downhole tool designed to be used with a passive RadioFrequency Identification (RFID) tag using an active RFID tag, the methodcomprising: placing an RFID tag reader of the downhole tool in a listenonly mode in which the RFID tag reader does not transmit a stimulationsignal to a tag; and introducing an RFID tag arrangement according toclaim 1 into the wellbore; and transmitting a payload of the RFID tagarrangement to the RFID tag reader without stimulation by the RFID tagreader.
 15. The method of claim 14, wherein transmitting the payloadcomprises transmitting for a duration of 14-ms in transmission cyclesand resting for a period of 16-ms between the transmission cycles. 16.The method of claim 14, wherein transmitting the payload comprisestransmitting the payload as 12 bytes.
 17. The method of claim 14,further comprising configuring the RFID tag reader to transmit aprogramming signal to the RFID tag arrangement reprogramming the RFIDtag arrangement when RFID tag reader receives the payload.
 18. Themethod of claim 14, further comprising positioning the RFID tagarrangement in a carrier deployable downhole in the wellbore to thedownhole tool.